Spherical mill

Production of finished articles by machining or casting appeared several thousand years ago. Until now, this method remains the primary consideration. A manufacturer of slots and studs to connect the two parts, grooves of various shapes and sizes, engraving, shaped milling, etc.

while for rectangular and circular cavities not needed complex tools, to get seizures more complex forms it was necessary to find new design solutions. And so it proved in the case of spherical surfaces. With the help of traditional tools and methods it was very difficult to get a smooth surface, not speaking about their mass production.

the Solution came in the form of new design tools, which are called spherical cutter. What does it represent?

the What is ball mill

This cutter is the tool intended for machining of spherical recesses or ledges. Represents the body rotation. They are also called ball.

In General, consists of such elements as the cutting part and the shank. Therefore, they refer to the General class of end mills.

These cutters have from two to six teeth. The profile cutter has a spherical shape. Typically, the angle of the spherical area of the cutting edge is 180°. Available in versions with the magnitude of the angle is less or greater than 180°.

To remove chips from the cutting area on the cutter has spiral flutes. In the case of indexable they usually do not exist.

Shank can be produced in a cylindrical design, and in the form of a cone Morse. The use of the conical shape of the shank makes the instrument more durability. This allows you to produce longer tools used for machining deep grooves.

During the rotation of the cutter around its axis the cutting edge is the cutting layer of the workpiece. Due to the round shape provides the most complete contact with the surface.

However, in practice, this leads to some difficulties. Due to the spherical profile of the thickness of a removed shaving changing from the top edge to its radius. Also the angular velocity at the apex of the cutter is equal to zero. So, at this point cutting does not occur.

These problems are solved by oblique milling. This is the feed to the mill is performed at an angle.

These cutters are made usually of a carbide material. Some of its parts can be made of tool steel. To increase the wear resistance and strength characteristics of the cutting edge may be applied a coating of titanium nitride.

Widely used in following fields

— mechanical engineering;

— tool production;

— art milling;

— woodworking and carpentry.

Especially indispensable spherical cutters in the production of dies, molds and complex parts. Due to the round cutting edge, they allow to achieve the theoretically calculated surface taking into account the allowances. Also found its application in the creation of inscriptions on the surface of workpieces, in particular in a U-shaped engraving. Suitable for recovery of engraving.

these cutters are used for semi-finishing and finish machining of materials such as cast iron, steel, nonferrous metals, wood, plywood, plexiglass, acrylic. Chetyrehstolbovoy modification suitable for hard material, like hardened steel.

Varieties spherical cuttersdepending on the design and manner of implementation of the inserts is useful to distinguish several types of cutters. It is a spherical cutter with a removable or brazed cutters, with interchangeable heads.

This cutter is a one piece design. Partly because of this they are also called monolithic. Consists of a cylindrical shank and a cutting part.

Cutting inserts made of carbide material mounted in the cutter by ithuania. Because of this, first, provides a high strength to the whole structure of the instrument, and secondly, the torque from the machine spindle is transmitted as fully as possible the cutting edges.

To remove shavings from the processing area on the cutter has a helical groove with an angle of inclination of 30°. Its presence has a positive effect on the service life.

the Advantage of this tool is that they can process materials with hardness up to 45HRC. Usually they are made with diameter from 0,4 to 25 mm.

However, due to problems during processing owing to the spherical shape, the cost of this mill still remain high. Therefore, options have been proposed with interchangeable cutters and head.

the ball mill removable cuttersthese cutters are used in cases when it is not needed to achieve high quality processing and there is a need in large diameter up to 50 mm. Here the shank can be made in cylindrical, conical form.

Carbide inserts mounted in the grooves and secured by fasteners. Usually they are in the mill two and they are located symmetrically relative to the axis.

Due to the shift of plates for large scale production is achieved good economic effect.

are mainly Used for medium and rough machining of titanium, hardened steel, ferrous and non-ferrous metals.

This cutter is between the solid and with removable cutters in the diameter range. They come with this size from 6 to 25 mm. they are also approximately in the middle provide for clean processing.

you Can say that this tool with interchangeable heads is the result of evolutionary development end mills.

Consists of a replaceable head, which is screwed into the shank. On the head of the located teeth. As a rule, the number of teeth may be from 4 to 6.

Often interchangeable head is made from solid carbide materials, and the remainder of steel. At the same time there is a modification in which the shank is also made of hard alloy. The surface of the cutting edges may be coated for work with particularly hard materials like titanium alloys.

Thanks to all that strength characteristics of the instrument almost as close to those of the monolithic cutters.

Usually groove for ejection of the chips has a helical shape. On its surface can be applied a special coating to improve the ejection velocity.

From the nuances it should be noted that to achieve a clean machined surface, it is recommended to give the rotary motion of the mill. This is done to avoid the so-called points, in which the speed of the cutter equal to zero.

Like all end mills, this type of tools strongly heated and there is a necessity for cooling the cutting zone of the workpiece. For this purpose, an emulsion of liquid.

In General, the selection of the cutter depends on the workpiece material, the size of the required cut and the process parameters.